It's nothing to do with the post and any card delivery. You have to wait 14 days after purchase before the benefits (i.e. preferential ticket purchase) kick in. So unfortunately it will be early next week.
Ridiculous. Probably saves someone in the office transferring the seating plan system and setting up for us plebs to use. Alternatively, that what comes of selling tickets seven weeks in advance.
Are people happy with the seats you have now been allocated for Watford ?